Cell Line Development

Our mammalian expression Cell Line Development packages are available to bridge the gap between pre-clinical discovery and GMP process and manufacturing development. We have experience in developing cell lines in CHO, NS0 and other cell backgrounds.

In addition to engineering cells for high expression of secreted proteins, we can engineer cells to display surface molecules of interest or to provide disease models.

At all stages during the design, execution and post delivery phase of the project, Accuro Biologics maintains the highest standards of ongoing customer feedback and support.

Cell Line Development programmes involve the following key elements:

• Compilation of the desired expression vector system. Vectors are assembled in house by our molecular biology team. For antibody expression projects, vectors comprise genomic elements (immunoglobulin genes) and are free of significant intellectual property burdens. Vector assembly is comprehensively documented with double strand sequence analysis conducted for all newly assembled expression cassettes. Where appropriate, functional validation of the vector is conducted using transient transfection assay and analysis of the expressed protein of interest.
• Stable transfection of host cells. In most instances electroporation provides the method of choice. This may be conducted in serum-free conditions if required for certain pre-adapted host lines. Other gene transfer procedures may be used if required or specified.
• Clone selection. Single clones with the highest productivity are isolated by limited dilution sub-cloning. FACS based screening / selection procedures can be developed or applied as appropriate.
• Cryopreservation of cells is conducted at each generation stage. Standard procedures ensure project and strain segregation during clone development and storage. Our standard procedures include routine monitoring for mycoplasma.
• Productivity determination. Volumetric productivity (mg/litre) in static culture or shake flask conditions is determined using ELISA or other assay methods directly on culture supernatant during clone development. Surface expressed molecules may be measured using FACS as appropriate.
• Specific Productivity. Critical for comparability and clone selection, specific productivity determinations (pg/cell/day) are conducted over the optimal time window in the culture cycle. Determinations give insight into the generation time and other base line parameters required for process development.
• Stability studies. Typical studies verify stability of expression over 30 or more generations. If required adaptation to serum-free culture conditions may be integrated with stability assessment.

Manufacturing Cell Lines

Cell lines destined to become the seed stock for Master Cell Bank (MCB) and full manufacturing process development are established with due regard to current ICH guidance and best practice to support subsequent regulatory approval and manufacturing applications.

Such cell lines - cell substrates - are developed using fully documented host stocks, are cultured using certificated media, media supplements and culture consumables. Projects are delivered with fully documented cell development histories, Certificates of Analysis and data packages.

See also: Antibody Engineering | Protein Engineering | Immunogenicity Profiling

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